1
A bone is ____________ working together
several tissues
Is carbon dioxide organic?
No, it does not have a carbon-hydrogen bond
What is the functional unit of compact bone
Osteon
Long bone examples
Humerus, Tibia, Fibula, Femur
Length is greater than width
In initial and embryonic development, what type of bone comes first
What are the multiple tissues working to create a bone?
Ligaments, tendons, cartilage and bone itself
What produces collagen
Fibroblasts
Weight bearing causes microfractures in bone, as osteoclasts _________ and osteoblasts _______ which makes you _______ when active
clear out old and damaged bone
Lay down new bone
Stronger
Short bone examples
carpals, tarsals (cubbish in appearance) length and width almost the same
In woven do the collagen fibers go in uniform direction or random direction
Randomly in every direction
Why does cartilage heal slowly?
Because the blood vessels do not penetrate the cartilage, but rather go on the sides of it
If I have a sample of a femur and a sample of a tarsal under the microscope, can I tell if they have been remodeled?
No, they will look the same
After woven bone remodels it becomes what type of bone and why do we see concentric rings
lamellar bone, they create circles around
Flat bone examples
Skull, ribs, sternum, scapulae and part of mandible
Osteoclasts remove old bone and osteoblasts add new, and the woven bone is remodeled into lamellar bone which has concentric circles
What percent of lean mass is bone?
18%
What forms the shape of a bone?
Cartilage embryonically
What is a ruffle border?
The border where the osteoclasts are found absorbing old and damaged bone
Irregular
Patella, vertebrae, and facial
What is lamellar bone
Mature bone in sheets
In bone development, why do you need Ca, P and amino acids available?
Ca and P for Calcium Phosphate salts (hydroxyapatite)
Amino acids to create the protein: collagen
Why do bones have both spongy parts and compact parts
If the whole bone was compact it would be so dense and heavy we would not be able to walk correctly, as the spongy bone is porous and open making it easier to move
What process occurs between the ruffled border and osteoclast?
The H+ ion (proton) is pumped out of the osteoclasts and pumped into the bone as Ca+ and P are liberated from the matrix of that area
Also H+ is acidic and that is how the osteoclasts digest the old bone by dissolving it
Do lacunae and canaliculi have fluid in them? If yes, then why would they?
They have fluid to transport nutrients and waste through the gap junctions between them
What direction does lamellar bone go in
Fibers are oriented in one direction in each layer, but in different directions the further out the layers go to maintain the strength of the bone